The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into the engine is regulated via a throttle. More specifically, the throttle adjusts throttle area, which increases or decreases air flow into the engine. As the throttle area increases, the air flow into the engine increases. A fuel control system adjusts the rate that fuel is injected to provide a desired air/fuel mixture to the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.
In spark-ignition engines, spark initiates combustion of an air/fuel mixture provided to the cylinders. In compression-ignition engines, compression in the cylinders combusts the air/fuel mixture provided to the cylinders. Spark timing and air flow may be the primary mechanisms for adjusting the torque output of spark-ignition engines, while fuel flow may be the primary mechanism for adjusting the torque output of compression-ignition engines.
Engine control systems have been developed to control engine operation to achieve desired power and torque, increased fuel efficiency, and reduced emissions. More specifically, model predictive control (MPC) principles have been applied to engine control systems. Examples of engine control systems utilizing MPC may be found for example in U.S. Pat. Nos. 9,328,671, 9,334,815, 9,378,594, 9,399,959, 9,435,274, 9,599,053 and U.S. patent application Ser. Nos. 15/429,219, 15/433,511, 15/465,909, and 15/487,150, the entire disclosure of each of which are hereby incorporated by reference. While engine control system achieve their intended purpose, there is a need for an improved engine control method that includes faster response and improved control accuracy.